Highest temperature in Tokyo on June 30?

Platform comparison

Market context

The real-world event this market tracks is the peak daytime heat at Tokyo Haneda Airport on 30 June 2026, measured in degrees Celsius. Current Japan Meteorological Agency forecasts predict cloudy skies with highs in the mid-to-upper 20s, making a 0% probability for extreme heat consistent with the data. Historically, Tokyo has seen volatile June temperatures; while Nerima Ward recorded 38.6°C during Japan’s hottest June on record, recent years show cooler trends, with central Tokyo failing to reach 25°C for seven consecutive days in late June. This divergence frames the current market probability: the 99% crowd-implied chance for 27°C aligns with the average high of 27°C for June, suggesting the market expects typical rather than record-breaking conditions.

Traders approaching this programmatically should monitor hourly Wunderground updates for Haneda, as the resolution source is the highest temperature recorded at any time on that day. Key catalysts include the onset of the rainy season, which typically suppresses peak temperatures, and any sudden shifts in cloud cover or wind patterns. A recent report from The Watchers News highlights that Japan endured its hottest June on record in 2025, with temperatures hitting 39.1°C in Kumagaya, but this year’s forecast suggests a return to average. Conditional orders should be set to trigger if real-time data exceeds 28°C, as this would invalidate the current 27°C frontrunner. Dependencies include the reliability of Wunderground’s historical data feed and the timing of the settlement window, which ends at 12:00 UTC on 30 June.

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Methodology

This page reviews Highest temperature in Tokyo on June 30? across five venues. The live probability is the Polymarket mid-price, sourced directly from the on-chain Polygon order book; the comparison columns benchmark each venue on fee structure, KYC, settlement currency and payment rails. Every CTA routes to Polymarket Review UK, which mirrors the Polymarket order book at 0% fees.

Resolution & payout

Polymarket-based markets settle through the UMA Optimistic Oracle on Polygon. A proposer submits the outcome, a two-hour challenge window opens, and unchallenged proposals finalise the resolution. Payouts settle automatically in USDC the moment the result is final — no bookmaker, no delay.

Kalshi-based markets settle in USD via the CFTC-regulated clearinghouse. Betfair Exchange settles in GBP/EUR net of commission. Manifold is play-money and does not pay out real funds.

FAQ

Where can I trade this market with the lowest fees?

Polymarket is geo-blocked in the US/UK/EU. The easiest 0%-fee broker into the same order book is Polymarket Review UK. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

Is this market available outside the US?

Polymarket itself is geo-blocked in the US/UK/EU. Always check the legal status of prediction markets in your jurisdiction before trading.

How does resolution work?

Through the UMA Optimistic Oracle on Polygon: a proposer submits the outcome, a two-hour challenge window opens, and USDC payouts settle automatically once the result is final.

What's the difference between YES and NO shares?

A YES share pays $1.00 if the event happens, $0 otherwise. A NO share pays $1.00 if the event doesn't happen. The market price between 0¢ and 100¢ is the implied probability.

Do I need to KYC for this market?

On Polymarket directly, no — it's wallet-based. Intermediary brokers like Polymarket Review UK trigger KYC only above $1,500 of lifetime trading volume; under that you trade pseudonymously with a single wallet address.